NFe.Components.FTP.ConnectDataSocket C# (CSharp) Метод

        private void ConnectDataSocket()		// #######################################
        {
            if (data_sock != null)		// already connected (always so if passive mode)
                return;

            try
            {
#if (FTP_DEBUG)
				Console.WriteLine("Accepting the data connection.");
#endif
                data_sock = listening_sock.Accept();	// Accept is blocking
                listening_sock.Close();
                listening_sock = null;

                if (data_sock == null)
                {
                    throw new Exception("Winsock error: " +
                        Convert.ToString(System.Runtime.InteropServices.Marshal.GetLastWin32Error()));
                }
#if (FTP_DEBUG)
				Console.WriteLine("Connected.");
#endif
            }
            catch (Exception ex)
            {
                throw new Exception("Failed to connect for data transfer: " + ex.Message);
            }
        }